Controlling electrical currents.



No. 656,324. Patented Aug. 2|, I900; A.. B. HOLMES.

CDNTROLLING ELECTRICAL CURRENTS.

(Application filed Apr. 11, 1899.) Q N o H o d e l m V R R J Q I AT'IORIIEYS we Noarus rn-zns cov wow-mm" wjSNINr-Tow. u. c,

Nrrno STATES ARTHUR BROMLEY HOLMES, or LIVERPOOL, ENGLAND.

CONTROLLHNG ELECTRICAL CURRENTS'.

srnorrrc'n'rrou forming part of Letters Patent No, 656,324, dated August 21, 1906.

To all whom it may concern: Be it known that I, ARTHUR BROMLEY HOLMES, a subject of the Queen of England, and a resident of Liverpool, England, have invented certain new and useful Improvements Gonnectedwith the Controlling of Electrical Circuits, of which the following is a specification.

This invention has reference to the con- IO trolling of electrical circuits such as those of electric-lightand power-service systems; and it has more particularly for its object to provide a mode of controlling such circuits by which when a short circuit or overload arises the abnormal current so caused shall be reduced'and -.the circuit automatically restored to the normal condition when the cause of overload has been removed. According to this invention (in thecaseof a short-circuit 2o overload taking place in the circuit) the object and efiect referred to are attained by. causing, by a controlling mechanism operating and arranged ashereinafter described, the normal circuit to be broken and the current '2 5 to be passed through asecondary connection or branch of the main circuit in which a resistance is employed. In the carrying out of this mode of controlling the circuit there is,

employed a mechanism of an automatic kind so arranged that when an excess of current takes place it causes the main circuit or line to be broken and the current to be passed through the secondary'connection containing the resistance, and it keeps the main-line circuit broken until the short circuit or overload is rectified.

The diagrammatic drawing hereto annexed Y illustrates the invention.

In the drawing the lines a and Z may rep o resent two conductors-namely, the supply and return-of a circuit supplying electrical energy to lamps Zor a motor m or other mechanism orthing absorbing electrical energy.

m may represent the source oftheelectrical pp y- The automatic electrical device for'openin g andolosing the, main-circuit conductor a in circumstances such as referred to consists of r a solenoid s, forming part of the circuit and p through which the whole current passes, two

,cups c,;containi'ng mercury, form ng the ter- '-minals at';the point of opening and closing Application filed April 11,1899. Serial No. 712,666. (No model.)

the circuit onthe line a, a contaotfork f, working in connection with the merc ury-cups c, a core k, operated by the solenoid s, and a lever d, fulcrumed' at e and suspending from one arm the core 75 and from the other a fork f. The lever (1 will be approximately-balanced by the adjustable weight w on one arm of the lever d. a

The weight w on the arm 10 tends always to keep the forks f in the mercury in the cups 0 and the core is out of the solenoid s, so that there is always a moment on the side of the lever-fulcrum e, acting against the core 70.

The secondary or branch circuit(designated a, terminating in the two'cups o. This branch circuit has a resistance r in it and a solenoid 8' directly under the solenoid s, such solenoid being so arranged in relation to the solenoid s and the core 70 that it acts upon the core when such core has first been moved down to come under its active influence by the mainline solenoid 8-that is, whenever an excess place.

In action when a fault in the circuit takes place-say a short circnit and an excess of current passes through the main conductor a, the solenoid-core la is drawn down by the somercury in the cups 0 against the weight w, and consequently the direct main circuit-line a is opened. As the fork f leaves the mercury terminals the current will pass by way of the branch circuit 0,and the core khaving pbeen brought under the action of the second solenoid s it will be held by this second or branch circuit solenoid andwill keep the mai1rline circuit by way of the terminal cups 0 open, and it holds the weight w upin the po sition shown in dotted lines against a stop 12. This condition will exist so longas an excess of current is passing. ance r in the-branchcircuit o prevents the line or section of a line on which the apparatus is used being damaged, and the lamps, motors, or what not used in the circuit are or overload in the circuit has been removed, the circuit through the main line a by way of the cups 0 and fork f is restored by this automatic mechanism through the weight w'- o) connects the two parts of the circuit-line ive current from causes as specified has taken Of course the resist thus protected from injury. When the fault lenoid s and the fork f is withdrawn from the T namely, as soon as the normal current passes through the circuit the force of the solenoids on the core It becomes less than the moment of the weight 'w, and consequently the arm.

of the lever carr *ingthe forkfis moved down, the forkfenters the mercury in the cups 0, and the normal or main circuit by way of these cups and fork is reestablished.

This invention may be usefully applied to circuits supplied by accumulators, feeders of electrical railways, or the connections of sections of a line of electrical railway, the feeders for electric light or power of an electricity-supply station, or the protection of a numof dynamos working in parallel, and similar or analogous applications.

What is claimed in respect of the hereindescribed invention is 1. In an electric circuit, a circuit opening and closing device, adapted automatically to normally close and keep closed the main circuit; an electromagnetic device connected with said opening and closing device, and operated by the current passed through the main-current wires, and adapted to actuate said device and open the main circuit when an excess of current takes place, and a branch circuit connecting the two ends of the line on either side of the point at which the circuit is closed and broken, and through which the whole current is adapted tov pass when the said main circuit-line is opened, a resistance on said branch circuit, and an electromagnetic device on and operated by the currentpassed through said branch circuit, and directly connected with the said circuit opening and closing device in the main circuitconductor, and adapted to keep the said main circuit open by its action on said circuit opening and closing device, while an excess of current continues, substantially as described.

2. In an electric circuit, comprising supply ceases and return conductors a and b, an electricitysupply source 00, and an electricity-consum ing apparatus-as Z mon the said circuit; a circuit opening and closing device on the conductor a; a solenoid s on the conductor a between the source a; and said opening and closing device; a core 76 connected with said opening and closing device, and operated by the solenoid s, to open the said circuit; a branch circuit 0 connecting the two parts of the main conductor a on either side of the terminals of the opening and closing device; a resistance 7' on the branch circuit 0; a solenoid s on said circuit, adapted to influence the core 70 in the same direction as the solenoid s to open the main circuit; and a weight or spring connected with the opening and closing device, and acting in a contrary direction to the solenoids, and normally adapted to close the said circuit and keep it closed; substantially as set forth.

3. The combination in the main conductors a and b, of an electric circuit, of the solenoid s on the conductor a; contact-terminals 0; connecting and disconnecting device J" Working in connection with c; a core 75 Working in connection with the solenoid s to open the main circuit by withdrawing the contacts 0; a lever (1 connecting the core 7t and contact device f; a weight w connected with the lever (Z and tending normally to operate the connecting devicef, and to close the circuit;

the branch circuit 0; a resistance 1' thereon; and solenoid 8 adapted to operate on the core 70 in the same direction as the solcnoid s, as set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses.

ARTHUR BROMLEY HOLMES. Witnesses:

JOHN HENDLEY W ALKER, FRANK E. FLnnTwooD. 

